Why do mouth injuries seem to heal faster than injuries on other body parts?

The title pretty much explains the question at hand, but a slight elaboration:

This morning I woke up to find my top (innerish) lip was split pretty badly down the middle. In fact, my lip was bleeding from a deep looking wound (still not sure what caused it- another mystery!).

A few minutes ago I looked at my lip (8 hours later) to find that the wound was completely not there anymore. I couldn't even feel a ridge from the wound I was bleeding from not all that long ago.

Then I realized that mouth injuries seem to heal faster than injuries to other parts of the body. I remember many times biting my cheeks or tongue only to discover they were completely healed a few hours later. When I cut my arm on something, it heals up slowly, scabs, then the scar usually stays "puffy" for a few days before settling down.

Surely I'm not the only one to notice this (I hope!)? Does the body just realize that the warm, wet mouth is a great breeding ground for bacteria and try to heal that area as quickly as possible? Have I completely lost my mind?

Previous laboratory studies have suggested that SLPI is involved in the wound healing process. The protein, which is also found in fluids that bathe mucosal surfaces such as bronchial fluids, cervical fluids, and saliva, is a remarkably versatile substance. It has anti-inflammatory, anti-viral, anti-fungal, and anti-bacterial properties. In recent years, NIDCR investigators demonstrated that SLPI found in saliva blocks HIV-1 infection.

<snip>

Interestingly, the researchers note that the fact that animals tend to lick their wounds may be nature's way of delivering SLPI to the wound site via saliva.

It seems to me that the mouth is an area that needs to heal pretty fast. I mean, if you are unable to eat, the cut on your leg becomes an afterthought. I had two nasty cold sores a week ago, and they're both gone now, to my endless relief.

Also, I think I once read that the tongue heals faster than any other part of the body. If that's true, again, I expect the evolutionary reason would be something like what I suggested.

I was wondering something similar about the recovery time for Lasik surgery, for which the commercials say that you can go back to work the next day. Don't they basically cut your cornea before the laser does it's work? Does it heal that quickly?

A study was released long after this thread began, which indicates that saliva has strong healing qualities.

Quote:

"This study not only answers the biological question of why animals lick their wounds," said Gerald Weissmann, MD, Editor-in-Chief of The FASEB Journal, "it also explains why wounds in the mouth, like those of a tooth extraction, heal much faster than comparable wounds of the skin and bone."